In:
Biotechnology and Bioengineering, Wiley, Vol. 35, No. 7 ( 1990-03-25), p. 719-726
Abstract:
Production of various extracellular enzymes (the β‐lactamases from Streptomyces albus G, Streptomyces cacaoi, Actinomadura R39, and the DD ‐carboxypeptidase from Streptomyces R61) by genetically engineered Streptomyces lividans TK24 in Lennox broth medium reached a maximum after 36 to 48 h. Subsequently, the enzyme activity drastically decreased probably due to an increased pH value and the production of an inactivator by Streptomyces lividans . Protease activity did not seem to play a major role. The increased pH and inactivator synthesis are related to amino acid catabolism and generally result in cellularlysis. The use of a medium where the catabolism of amino acids was made less likely by the presence of glucose and NH 4 Cl and by buffering at pH 7.4 considerably inproved the yield. Furthermore, the water activity of the medium seemed to be an important parameter for the production of extracellular proteins by genetically engineered Streptomyces . Better production was observed when the water activity was decreased to 0.96–0.98 by addition of sucrose. Under those conditions, the concentration of extracellular enzyme reached about 0.3 g (1 g in the best case)/L of culture supernantant.
Type of Medium:
Online Resource
ISSN:
0006-3592
,
1097-0290
DOI:
10.1002/bit.260350709
Language:
English
Publisher:
Wiley
Publication Date:
1990
detail.hit.zdb_id:
1480809-2
detail.hit.zdb_id:
280318-5
SSG:
12
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